The former CEO of one of the largest pain clinic companies in Tennessee is accused of plotting to forge the signature of a dead patient so Medicaid could be billed in her name, according to newly released federal court documents.

Both Davis and Montgomery have been indicted for the scheme and pleaded not guilty in federal court. Federal prosecutors revealed the forgery allegation for the first time this week, saying in court records they plan to introduce the email as evidence in Davis’ upcoming trial.

Comprehensive Pain Specialists, or CPS, was a Brentwood-based pain clinic company that rapidly collapsed this summer, giving little warning to patients or employees. It once was one of the largest pain clinic companies in the Southeast, treating more than 40,000 patients a month across dozens of clinics in eight states.

Davis, who was the CEO of CPS from 2011 to 2017, was indicted in April, three months before the company was shuttered in July. Prosecutors have said in court documents that his prosecution has little to do with the direct operations of CPS, and instead relate to a “side agreement” he had worked out with Montgomery, who was the head of a medical device company named CCC Medical Inc.

According to federal court documents, prosecutors allege that Montgomery would pay kickbacks to Davis so he would refer CPS patients who needed medical devices to CCC Medical. Montgomery allegedly used the referred patients to bill Medicare for at least $4.6 million, for which she received about $2.6 million in reimbursements. Montgomery allegedly paid Davis at least $770,000 in bribes and disguised some of the payments through the purchase of a sham company.

Legal fight over CPS email server

Davis' prosecution has now come to focus on a legal fight over the CPS email server, which prosecutors say contains millions of documents. This server appears to be where authorities first discovered the email about forging the signature of the dead patient.

In court motions, Davis’ attorneys have requested law enforcement turn over a copy of the entire server, which they argue will provide context to the email exchanges between Davis and Montgomery. Prosecutors have argued against the request, saying they have already turned over more than 100,000 documents, and it is unclear how any additional emails could put the forgery plot in "appropriate context."

"(Davis) is saying he is making his request in good faith, and is not engaging in a fishing expedition,” federal prosecutors wrote in court records. “However, (he) appears to be standing on the pier with tackle ready.”

Davis’ attorney, Kimberly Hodde, did not respond to a request for comment.